Force transmitting member



Sept. 20, 1949. c. F. BACHLE FORCE TRANSMITTING MEMBER Filed April 27, 1946 INVENTOR. Car/ F 5066/8 Patented Sept. 20, 1949 FORCE TRANSMITTING MEMBER Carl F. Bachle, Detroit, Mich., assignor, by mesne assignments, to Continental Motors Corporation, Detroit, Mich., a corporation of Virginia Application April 27, 1946, Serial N0. 665,467

8 Claims.

This invention relates to a force transmitting member, such as a rocker arm in the valve actuating mechanism of an internal combustion enmm.

In heavy-duty and high speed internal combustion engines, it is often necessary to provide very strong springs on the valves to insure proper closing. But strong valve-closing springs put an unusually heavy load on the valve actuating mechanism. In some types of engines, such as overhead valve types, the valve actuating mechanism includes a rocker arm. In order to reduc losses to a minimum, it is desirable to provide anti-friction devices wherever possible, as, for example, where the rocker arm engages the camshaft. In cases of this type, however, the problem is to provide an anti-friction device of sur cient strength to withstand the heavy loads involved.

It is the object of this invention to provide a force transmitting member, such as a rocker arm, in which the force in question is transmitted at one end to a member so constructed as to provide great strength while at the same time power losses are kept to a minimum by keeping friction to a minimum. This object is accomplished by means of a contact or bearing member in the form of a roller, rotatably mounted on a hub of softer material than the roller. The hub is mounted on a pin; hub and pin are keyed together against relative rotation, and the pin is secured against rotation relatively to the rocker arm. Sufficient clearance is provided between the roller and the hub to permit the formation of an oil film between them.

In the drawings:

Fig. 1 is a view in elevation of a rocker arm assembly embodying the features of this invention.

Fig. 2 is a partial section along the broken line 22 of Fig. 1.

Fig. 3 is a view in section along line 33 of Fig. 2.

Fig. 4 is an enlarged detail view of pin 8 shown before the ends are rolled over in the process of assembly; and

Fig. 5 is an enlarged detail view of the lock-pin used in the assembly.

In the embodiment shown, a force transmitting member such as a rocker arm 2 is adapted to pivot about the axis of any suitable stationary shaft cooperating with opening 4 in the rocker arm. At one end of rocker 2 there is provided a bifurcated member having fingers 6. Fingers 6 are provided with coaxial holes in which is mounted a pin 8. A hub I0 is mounted on pin 8. A lock pin I2 is disposed between pin 8 and hub H] to maintain these two parts in non-rotative relation to each other. Pin 8 and hub l0 together are held non-rotative relative to the rocker arm by rolling the ends of pin 8, as described below.

Pin 8 is grooved as shown at IA of Fig. 4 to receive the lock pin 12.. As shown in this embodiment, the axis of lock pin I2 falls substantially on the perimeter of contact between pin 8 and hub I0 so that lock pin l2 lies approximately half in groove M of pin 8 and half in a similar groove in hub i0. Also as shown in this embodiment, the ends I6 of lock pin l2 have been machined down so as to present a curved surface l8 having substantially the same radius of curvature as pin 8. If necessary to secure greater locking of pin 8 and hub l0 relatively to the rocker arm, it may be desirable to dispense with the machined ends I6 of lock pin l2, and extend the complete unbroken cylinder of lock pin l2 into cooperating grooves in the fingers 6 of the bifurcated arm. In assembling the completed rocker arm, the ends of pin 8 will be rolled over securely against the edges of the coaxial openings in fingers 6, in order to secure pin 8 against rotation relatively to the rocker arm. This rolling of the ends has been found sufiicient to prevent turning of pin 8 on the fingers 6, without requiring any key between the pin 8 and the fingers.

A contact or bearing member, shown as a roller 20 is rotatably mounted on hub Ill. Hub I0 and roller 20 will be made of materials so chosen that substantially all of the Wear between the two members will take place on hub I0. Ordinarily roller 20 will be of hardened steel and hub ID will be of a relatively soft bearing material such as bronze. Sufficient clearance will be provided between the inside diameter of roller 20 and the outer diameter of hub [D so that when a contact force is applied in the direction of arrow 22, a small crescent-shaped annular space 24 is formed between roller 20 and hub l0 opposite the point of application of the force in question. Crescentshaped space 24 will be large enough to permit the formation therein of an oil film which may be carried around into the region of contact between hub l0 and roller 20. Oil may be fed to the roller by means of passages 26 and 28 provided in rocker 2.

Operation When the completed rocker arm is first assembled, hub III will be substantially circular in cross section, as will roller '20. However, as roller 20, of

The extent, of this contact area will depend on the intensity of the force represented by arrowifl-andfitl'iesottness of hub l relative to roller 20. Thus a bear- 'ing contact area will automatically form between hub in and roller 20. This contactareawiilibe.as. much as, but no greater than, is necessary for'the load in question, and will thereforebea minimiim under the load conditions in existence and accordingly will ofier a minimum of frictional resistance to rotation. I

'It -will be seen from the foregoing that it is extremely important that hub l0 be held nonrotative in: relation to rocker arm 2- because rotation of hub I 0 would move the contact area-outof the line of force represented byarrow 22'; It is therefore imperative that hub Ill be securely locked against rotation.

Iclaim:

1. Ina rocker arm, a" bifurcated member having coaxial openingsthroughthe two fingers, a pin non-rotatably mounted in the openings of the fingers, a soft-metal hub positively mounted against rotation on the pin, and-abearing member rotatably' mounted on the hub.

2.- A rocker arm having a bifurcated member;

a a pin non-rotatably mounted'in the two' fingers of the bifurcated member, a soft-metal hub positively mounted against rotation onthepin; and'a hard-metalroller rotatably'mounted on the hub.

3. In a rocker arm assembly, a. bifurcated arm having coaxial openings through the fingers of the bifurcated'member, a; pin mountedlin the openings 7 of the fingers, at soft-metal hub mounted on the pin, a lock member between thelpin' and the hub, means to secure the pin against rotation relatively to the bifurcated. arm, and a. bearing member mounted on the .hub,.the' bearing member beingof harder materialjthan the. hub..

4. In a rocker assembly, abifurcated'member, a. pin mounted. in the fingers ofv the; bifurcated member, ahubmountedont-he .pin,. positi've.means 4 non-rotative in relation to each other, means to secure the pin non-rotative in relation to, the bifurcated member, and a bearing member of harder material than the hub hub.

5. The invention set forth in claim 4, in which the inside diameter of the bearing, member is suffieiently; larger than the outside diameter ,of the hub to permit the formation of an oil film between the hub and the bearing member.

6. A valve actuating member having a bifurdated arm, a. pin non-rotatably mounted in the bifurcated arm, a hub positively mounted against rotation on the pin; and a bearing member "of Harder mater-rat than the hub rotatably mounted on the hub, the bearing member having an interrial diameter sufficiently larger than the external diameter of the hub to permit the formation of an oil filin between the-bearing member and the hub.. "7."A-' valve actuating member" having a. bifur:

cated' arm, a pin mounted in the" arm; a hub mounted on the pin, a lock-pin between'the" pin and the hub, the ends of the first-named pin being securely roiled over against the sides ofthe. arm

to holdthe pin non-rotatable'in' the arm, and a 7 bearing'm'em'ber of harder material than thehub engaging. the pin andthe hubto maintain them rotatably mounted on the hub.

8; A valve actuating member-having a bifurcated" arm, a pin mounted in the arm, a' hub mounted on the pin, a lock-pin between'thepin and-the hub, the ends of the first-named pin being" securely rolled over against the sides of the arm 7 to hold the pin non-rotatable in the arm; and a roller of" harder material" thanv the hub'rbtatably mounted on'the hub, the'rolier having an interrial diameter sufficiently larger than the external diameter" of the hub to' permit the formation Oran;

oil film between the roller. and the hub.

smiterenna;

' file of this patent:

7 UNITED PAIENTS Number Name .7 7 l ate 842,84? v Masons. Jan. 29', :190f7 1,763,95'7 Elliott June. 17:, I930 2,010,378. Sassen Aug/6,, 1935 2,054,928 Church Sept. 2211936 2,222,694,

rotatably mounted on the 

